Potassium Carbonate → 4-Oxo Etodolac

HRID 1253289Notes

Reaction equation

HRID 1253289 reaction equation
C[O:2][C:3](=[O:23])[CH2:4][C:5]1([CH2:21][CH3:22])[C:10]2[NH:11][C:12]3[C:17]([C:9]=2[C:8](=[O:20])[CH2:7][O:6]1)=[CH:16][CH:15]=[CH:14][C:13]=3[CH2:18][CH3:19].C([O-])([O-])=O.[K+].[K+]>CO.O>[CH2:21]([C:5]1([CH2:4][C:3]([OH:23])=[O:2])[C:10]2[NH:11][C:12]3[C:17]([C:9]=2[C:8](=[O:20])[CH2:7][O:6]1)=[CH:16][CH:15]=[CH:14][C:13]=3[CH2:18][CH3:19])[CH3:22]

Participants

5

Reactant 2

HCID 11430Potassium CarbonateHCID 11120627Methyl (1,8-diethyl-4-oxo-1,3,4,9-tetrahydropyrano[3,4-b]indol-1-yl)acetate

Product 1

HCID 112665954-Oxo EtodolacYield 93%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 962WaterSolvent

Procedure

1,8-Diethyl-1,3,4,9-tetrahydro-4-oxopyrano[3,4-b]indole-1-acetic acid methyl ester 17 (1.5 g, 4.8 mmol) was suspended in 30 mL of MeOH and a solution of K2CO3 (3.5 g) in 30 mL of H2O was added. The mixture was heated to reflux, upon which the solution became homogeneous. After refluxing for 2 hours, the solution was cooled to room temperature, and the MeOH removed in vacuo. The aqueous solution was made acidic with 6N HCl, and the resulting cloudy solution was extracted with ether (2×50 mL). The ether layer was washed with 25 mL of saturated NaCl solution, then dried over MgSO4. The MgSO4 was removed and the ether was evaporated. Hexane was gradually added until a slight turbidity was observed. The solution was left at 0° C. overnight and the resultant solid was collected by filtration and dried to provide analytically pure product (1.31 g, 93%), m.p. 200°-202° C.

Workup

  1. temperatureThe mixture was heated
  2. temperatureto reflux, upon which the solution
  3. temperatureAfter refluxing for 2 hours
  4. customthe MeOH removed in vacuo
  5. extractionthe resulting cloudy solution was extracted with ether (2×50 mL)
  6. washThe ether layer was washed with 25 mL of saturated NaCl solution
  7. dry with materialdried over MgSO4
  8. customThe MgSO4 was removed
  9. customthe ether was evaporated
  10. additionHexane was gradually added until a slight turbidity
  11. filtrationthe resultant solid was collected by filtration
  12. customdried

Sources & evidence

ORD record
ord-9ec9975a37634f148367f7ab36e66ab8
Source dataset
uspto-grants-1988_05
Patent number
US04748252

Reaction notes

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